The compound 1,3-diphenyl-2-propene-1-one is known by the trivial name "chalcone". Many naturally occurring flavonoids share structural features with chalcone and are referred to by the generic term "chalcones". Also, certain flavonoids, including ones which are also classified as chalcones, have recently been demonstrated to have anticancer activity (Cancer Research, 48, 5754, 1988) and chemopreventive activity in some tumours (J. Nat. Prod., 53, 23, 1990).
In particular, quercetin, an ubiquitous flavonoid found in plants, has been shown to act on the proliferation of human leukemic cells (Br. J. of Haematology, 75, 489, 1990) and on other cell lines (Br. J. Cancer, 62, 94, 942, 1990; Int. J. Cancer, 46, 112, 1990; Gynecologic Oncology, 45, 13, 1992) and to possess a synergic action with common antiblastic drugs.
In addition, some natural or synthetic chalcones, described in our International Patent Publication No. WO 91/17749 and in International Patent Publication No. WO 96/19209 (Baylor College of Medicine) have proved to have a significant antiproliferation activity on a variety of different cell lines.
Although the mechanism of action of the antiproliferation activity of flavonoids and chalcones is still unknown, it is believed to be linked to the interaction of these compounds with type II estrogen receptors.
The action in vivo of these polyphenol substances is certainly much more complicated. All these compounds are generally characterized by an almost complete insolubility in water and, in vivo, by a very poor bioavailability linked to a rapid metabolism of phenols and a marked affinity for lipids and proteins.